The present invention relates to a new and improved method of, and apparatus for, opening folded, bound or stitched multi-sheet products, especially printed products.
Generally speaking, the method and apparatus of the invention contemplates that the product which is to be opened is moved with a leading open side thereof towards a stationary separation element which moves between the sheets of the product and the printed product is moved past such stationary separation element.
There are already known to the art different opening devices for printed products, by means of which, with the aid of a pre-separator element, the sheets of the product or article being processed are separated from one another at a certain region thereof. Thereafter, a separator element is introduced into the thus formed gap, to thereby assume the task of completely opening the product. According to one prior art construction of such product or article opening apparatus, as the same has been disclosed in German Patent Publication No. 2,447,336 and the corresponding U.S. Pat. No. 3,951,399, the pre-separator element is a pressure element which exerts a compressive force at the folded product, this force being directed transversely to the flat side of such product. As a result there is caused bowing-out of part of the sheets. Into the thus formed gap there is introduced a separator or separation element which completely opens the product. Since the mode of operation of this equipment is predicated upon the presence of a pre-bias or pre-stress in the product which is governed by the folding of the product, it is only possible to open certain types of products with this technique. Additionally, during the pre-separation operation the gap forms between the sheets located at opposite sides of the fold, so that there is not readily possible opening of the product at a different location.
Additionally, this type of product opening apparatus, along with all others working with the technique of carrying out a pre-separation and subsequent actual separation, have common thereto the drawback that the construction of the equipment is quite complicated.
Apart from the foregoing constructions there are known to the art other product or article handling apparatuses such as exemplified by U.S. Pat. Nos. 3,580,562, 3,692,301 and 3,722,877.